Vivica A. Fox: Jessica Simpson 'Diva' Rumors Are 'Lies'

Vivica A. Fox is shooting down talk of Jessica Simpson's alleged diva-like behavior on the set of their new film together, Major Movie Star – labeling recent reports nothing but "vicious lies."

Fox, a favorite on Dancing with the Stars, tells PEOPLE she was "shocked" when a story surfaced from Major Movie Star's Louisiana location accusing Simpson of being a "spoiled brat" by supposedly refusing to walk from one place to the next without a driver, eating alone in her trailer and barely speaking to her costars, especially Fox.

"Those vicious lies they put out were just that – lies," Fox, 43, said Saturday during an event for the fashion label Young, Fabulous & Broke at the LG House in Malibu.

In fact, Fox said that Simpson was anything but a diva. "She was so much of a team player. She was gracious and so down to earth."

In the comedy, which also stars Cheri Oteri and Steve Guttenberg, Simpson plays a movie star who suddenly falls from grace and finds herself broke. She then enlists in the U.S. Army with the hope the service will change her life.

Fox plays a tough sergeant who whips Simpson's character into shape. Speaking of Simpson, Fox said, "She showed a lot of physicality, like 90 percent of all her own stunts, and she sacrificed so much of her body for this movie"

Literally. While filming last week, Simpson accidentally injured her nose with a prop gun.

"During the scene," remembers Fox, "she looked really intense when I looked in her eyes, and I just thought she was really into it. But when the director [Steve Miner] yelled, 'Cut,' Jessica came over to me and said, 'Vivica I hit my nose with the gun.' "

Explains Fox, "We got ice immediately ... Most girls would've stopped right then and there, but she was ready to do another take. She's wonderful."